page_title: Traditional handheld refractometer
hierarchical_section_title: Traditional handheld refractometer
caption_attribution_description: Deutsch: Blick durch das Okular eines Handrefraktometers mit fixer Arbeitstemperatur (20 °C) bei der Analyse des Oechsle-Wertes einer frisch gepflückten Weintraube. Ablesewert: 47 °Oechsle.
context_page_description: A traditional handheld refractometer is an analog instrument for measuring a liquid's refractive index. It works on the critical angle principle by which lenses and prisms project a shadow line onto a small glass reticle inside the instrument, which is then viewed by the user through a magnifying eyepiece.
  In use, a sample is placed between a measuring prism and a small cover plate. Light traveling through the sample is either passed through to the reticle or totally internally reflected. The net effect is that a shadow line forms between the illuminated area and the dark area. It is where this shadow line crosses the scale that a reading is taken. Because refractive index is very temperature dependent, it is important to use a refractometer with automatic temperature compensation. Compensation is accomplished through the use of a small bi-metallic strip that moves a lens or prism in response to temperature changes. This design was invented by Emanuel Goldberg. There are many types of refractometers and the most common types are Abbe's refractometer, Pulfrich refractometer, Immersion refractometer.
context_section_description: A traditional handheld refractometer is an analog instrument for measuring a liquid's refractive index.  It works on the critical angle principle by which lenses and prisms project a shadow line onto a small glass reticle inside the instrument, which is then viewed by the user through a magnifying eyepiece. 
  In use, a sample is placed between a measuring prism and a small cover plate. Light traveling through the sample is either passed through to the reticle or totally internally reflected. The net effect is that a shadow line forms between the illuminated area and the dark area. It is where this shadow line crosses the scale that a reading is taken. Because refractive index is very temperature dependent, it is important to use a refractometer with automatic temperature compensation. Compensation is accomplished through the use of a small bi-metallic strip that moves a lens or prism in response to temperature changes. This design was invented by Emanuel Goldberg. There are many types of refractometers and the most common types are Abbe's refractometer, Pulfrich refractometer, Immersion refractometer.
caption: Ocular view on a handheld refractometer. Reading 46 °Oechsle.
exif: {"Image ImageWidth": "3264", "Image ImageLength": "2448", "Image Make": "SAMSUNG", "Image Model": "GT-I9195", "Image Orientation": "Horizontal (normal)", "Image XResolution": "98552/25", "Image YResolution": "98552/25", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop Elements 6.0 Windows", "Image DateTime": "2014:10:22 20:06:53", "Image YCbCrPositioning": "Centered", "Image ExifOffset": "260", "GPS GPSVersionID": "[2, 2, 0, 0]", "GPS GPSLatitudeRef": "N", "GPS GPSLatitude": "[49, 28, 1449/100]", "GPS GPSLongitudeRef": "E", "GPS GPSLongitude": "[8, 10, 1837/80]", "GPS GPSAltitudeRef": "0", "GPS GPSAltitude": "187", "GPS GPSTimeStamp": "[15, 45, 58]", "GPS GPSProcessingMethod": "ASCII", "GPS GPSDate": "2014:08:28", "Image GPSInfo": "2436", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "2762", "Thumbnail JPEGInterchangeFormatLength": "4649", "EXIF ExposureTime": "1/17", "EXIF FNumber": "13/5", "EXIF ExposureProgram": "Aperture Priority", "EXIF ISOSpeedRatings": "125", "EXIF ExifVersion": "0220", "EXIF DateTimeOriginal": "2014:08:28 17:45:54", "EXIF DateTimeDigitized": "2014:08:28 17:45:54", "EXIF ComponentsConfiguration": "YCbCr", "EXIF ShutterSpeedValue": "1/17", "EXIF ApertureValue": "69/25", "EXIF BrightnessValue": "76", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "69/25", "EXIF MeteringMode": "Average", "EXIF LightSource": "Unknown", "EXIF Flash": "Flash did not fire", "EXIF FocalLength": "37/10", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "1000", "EXIF ExifImageLength": "1000", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "EXIF InteroperabilityOffset": "2404", "EXIF SensingMethod": "One-chip color area", "EXIF SceneType": "Directly Photographed", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF DigitalZoomRatio": "1", "EXIF SceneCaptureType": "Standard", "EXIF Saturation": "Normal", "EXIF Sharpness": "Normal", "EXIF ImageUniqueID": "S08Q0LEGC01"}